If you have a manual check to see if the bobbin case is lined up right...I can't explain it here but if the needle plate has ever been taken off there are two grooves on it that must line up with the bobbin mechanizium. really hard to explain but I bought my FW on ebay and when it came it wouldn't sew and sure enough the bobbin case was flopping around. LOL Found this out on my 301 thru a good friend whose DH was a machine repair man. try it...it will not sew if its in wrong....sounds like it needs a really good oiling also...